Evaluation of the blood-brain barrier based on the functional analysis of transporters using newly developed techniques.

在本研究中，我们研究了具有血脑屏障功能的脑毛细血管内皮细胞中的膜转运体。通过这项研究，我们发现了三种新的在血脑屏障处表达的转运蛋白。其中一种转运蛋白是单羧酸转运蛋白MGT1，它可以吸收和/或排出乳酸、丙酮酸和苯甲酸等有机弱酸。第二个转运体是中性氨基酸转运体LAT1和LAT2。这两种氨基酸转运体的作用是吸收相对亲水的大分子氨基酸，包括亮氨酸、酪氨酸和苯丙氨酸。这些对于左旋多巴在大脑中的作用也很重要而左旋多巴对帕金森氏症很有效。第三种转运体是octn2，它被归类为肉碱/有机阳离子转运体。OCTN2是一种依赖Na^+的肉毒碱转运蛋白，对大脑摄取乙酰- l-龋齿起作用，预计对阿尔茨海默病有用。另一方面，大脑外排转运体保护大脑免受有毒外源性药物的侵害。本研究以h1 -拮抗剂依巴斯汀、卡巴斯汀和氟喹诺酮格雷帕沙星为模型药物。氟喹诺酮类药物和H1拮抗剂通常具有癫痫和镇静作用等不良反应，而本研究研究的药物未表现出此类不良反应。我们预计这些药物可能没有足够的通透性通过血脑屏障，导致没有足够的药物递送到大脑，从而产生不利的不良反应。对这些药物血脑屏障转运的各种研究表明，脑外排转运体至少有两种类型，包括p-糖蛋白和阴离子交换转运体，其分子鉴定仍有待成功。所有这些研究都是通过使用各种血脑屏障传输技术进行的。特别是从大鼠脑毛细血管内皮细胞中获得的新细胞系RBEC1为本研究的成功奠定了基础。此外，我们还挑战了内皮细胞和星形胶质细胞共同培养以模拟体内血脑屏障。虽然体外血脑屏障模型的制备取得了一定的成功，但为了建立高效、完整的血脑屏障运输评价模型，还需要进一步的改进。少

In the present study, we studied membrane transporters equippecd, in the brain capillary endothelial cells that are functional as the blood-brain barrier. Through this study, we found three new transporters that are expressed at the blood-brain barrier.One of those transporters are monocarboxylic acid transporter MGT1, which tworks for uptake and/or efflux organic weak acids such as lactic acid, pyruvic acid and benzoic acid. The second transporter is neutral amino acid transporters LAT1 and LAT2. These two amino acid transporters work for the uptake of amino acids that are relatively hydrdphpbic and large molecules, including leucine, tyrosine and phenylalanine. These are also important for the brain livery of L-DOPA that is effective for perkinsonism. The third transporter is OCTN2that is callsified as the carnitine/organic cation transporter. OCTN2 is a Na^+-dependent carnitine transporter and works for the brain uptake of acetyl-L-carhitirie that is expected to be useful for Aitzhe … More imer's disease. On the other hand, brain efflux transporters that protect brain from the toxic xenobiotics. As the model drugs, H1-antagonist, ebastine and carebasitine and fluoroquinolone, grepafloxacine, was used in the present study. Generally, fluoroquinolonesand H1 antagonists exhibit adverse effects such as epilepsy and sedative effects, while the drugs studied in the present study do not show such adverse effects. We expected that these drugs might not have enough permeability across the blood-brain barrier, resulting in the insufficient delivery to the brain to cause unfavorable adverse effects. Varipus Kinds of studies on the BBB transport of these drugs demonstrated that there are at least two types of brain efflux transporters, including p-glycoproteih and anion exchange transporter, of which molecular identification remains to be succeeded.All of these studies were performed by using various BBB-transport techniques. Especially, newly developed cell line RBEC1 that were derived from rat brain capillary endothelial cells was useful for the success of the present study. Furthermore, we challenged of the coculture of the endothelial cells and astrocytes in order to mimic the in vivo BBB. Although we partly succeeded to prepare the in vitro BBB model, further improvement will be essential for the efficient and complete model for the evaluation of blood-brain barrier transport. Less